A high current, high dI/dt, light activated thyristor

Solid-state switches are necessary for pulsed power systems which require long life, high reliability and high repeatability. However, state-of-the-art electrically gated thyristors cannot achieve the dI/dt rating necessary for the most advanced pulsed power systems. Optical activation of the thyristor can be utilized to drastically increase the dI/dt rating and thus the area of the switch is determined only by the temperature rise. The authors present experimental results of a novel optical activation technique which can be used to efficiently couple light into a large area thyristor. Using this technique, a single 6 kV, 77 mm thyristor conducted 111 kA with a 10-90% rise-time of 1.3 /spl mu/s and a pulse width of /spl sim/6 /spl mu/s. The circuit limited dI/dt was 85 kA//spl mu/s. In addition, two switches were operated in series to hold-off 12 kV and, when activated, conducted 108 kA with a 1.3 /spl mu/s risetime and a pulse width of /spl sim/6 /spl mu/s.